How many moles of water will be produced when 8 moles of ethane are burned?

The number of moles of water will be produced when 8.0 moles of ethane are burned = 24.0 mol.

Explanation:

It is a stichiometry problem. The balanced equation of burning ethane is:

2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O

It is clear that 2.0 moles of ethane (C₂H₆) burns in 7.0 moles of oxygen and produce 4.0 moles of CO₂ and 6.0 moles of H₂O.

Using cross multiplication:

2.0 moles of ethane produces → 6.0 moles of H₂O, from the stichiometry.

8.0 moles of ethane produces →? moles of H₂O.

∴ The number of moles of water will be produced when 8.0 moles of ethane are burned = (6.0 x 8.0) / (2.0) = 24.0 mol.